

Former presidents George H.W. Bush (l.) and his son, George W. Bush, receive a standing ovation as they arrive to throw the ceremonial first pitch at Game 4 of Major League Baseball's World Series between the San Francisco Giants and the Texas Rangers in Arlington, Texas, on Oct 31. Mike Segar/Reuters
San Francisco Giants' Cody Ross shakes hands with former presidents George Bush (l.) and his son, George W. Bush, at Game 4 of Major League Baseball's World Series between the Giants and the Texas Rangers in Arlington, Texas, on Oct 31. Matt Slocum/AP
Former US first ladies Barbara Bush (l.) and Laura Bush watch as their husbands, former presidents George H.W. Bush and George W. Bush, attend the ceremonial first pitch throwing prior to the start of Game 4 of Major League Baseball's World Series on Oct. 31. Matt Slocum/Reuters
Former President George W. Bush throws the ceremonial first pitch to Texas Rangers president Nolan Ryan before Game 4 of baseball's World Series between the San Francisco Giants and the Texas Rangers on Oct. 31 in Arlington, Texas. Eric Gay/AP
Former President George H.W. Bush (r.) watches his son, former President George W. Bush, throw a perfect strike for the ceremonial first pitch for Game 4 of baseball's World Series between the San Francisco Giants and the Texas Rangers in Arlington, Texas, on Oct. 31. George W. Bush's memoir, 'Decision Points,' hits shelves on November 9. Matt Slocum/AP
From left, former President George H.W. Bush; his wife, Barbara; and former President George W. Bush watch Game 4 of baseball's World Series between the San Francisco Giants and the Texas Rangers in Arlington, Texas, on Oct. 31. David J. Phillip/AP
Former first lady Laura Bush waves a towel beside former President George W. Bush as the Texas Rangers' Nelson Cruz (l.) stands on deck during the fourth inning of Game 4 of Major League Baseball's World Series between the San Francisco Giants and Texas Rangers, in Arlington, Texas, on Oct. 31. Brian Snyder/Reuters
Former President George H.W. Bush makes the Texas Rangers' 'claw and antlers' gesture during Game 4 of Major League Baseball's World Series against the San Francisco Giants, in Arlington, Texas, on Oct. 31. The Giants defeated the Rangers 4-0. Brian Snyder/Reuters